Contact pins and cantilevered spring contacts are widely used in various electrical and electronic products. Typically, the pair of cantilevered spring contacts are formed integrally with a barrel, rearwardly of the contacts, and the barrel is crimped about the bare portion of an insulated wire for electrical engagement with the contacts. The contacts, in turn, slidably receive the pin.
A plurality of closely-spaced pins are usually mounted on a plug and are adapted to engage a corresponding plurality of closely-spaced contacts in a receptacle or header. For example, the header may be mounted within a piece of electrical or electronic equipment, and the plug may be mounted on the end of a cable carried by another assembly.
In certain product applications, the contacts in the header are often exposed; and in order to protect the contacts, a protective sleeve may be provided. This protective sleeve is substantially cylindrical, surrounds and encloses the contacts, and is crimped on to a rear portion of the contacts.
The contacts may be made of aluminum or a tin-based alloy, for example, and if desired may be plated with a precious or semi-precious metal for superior conductivity. The sleeve, in turn, may be made of copper or any suitable material that is readily available and relatively inexpensive. Presently, the sleeve is made by a deep drawing process.
However, because of the continuous evolution in product miniaturization involving relatively-high circuit densities, it is difficult to form the sleeve by a deep drawing process and to handle the relatively small pieces involved. For example, the sleeve may have an outer diameter of roughly two or three millimeters.
Besides, there is no way to preclude an oversized pin from being inserted through the sleeve and between the contacts, thereby inadvertently damaging the contacts. This problem is especially pronounced where several cables and headers are available to an inexperienced non-technical person assembling or using the equipment.